Buying attendance first looks safest: who is in, who is late, numbers appear immediately. Whether leave was approved, who nodded overtime, and how travel matches punches still live in the group. HR is an island; the mainland work is still verbal.
The island shows up at month-end
Attendance says no-show; the employee says the group approved leave. Finance wants expense days; HR has another table. When they disagree, both sides edit spreadsheets and nobody owns the rule. From twenty to eighty people, that reconcile fails before the business does; see From 20 to 80 people, why management has to be systematized. Leave should be one approval flow, not a note in the attendance app.
HR-only also creates an illusion that org permissions are done. What you have is a directory, not “who can approve a contract” or “who can see salary.” Permissions stay verbal; see Why verbal permission rules eventually fail. New hires can punch in and still cannot find policy or flows. Knowledge base and approval entry are missing; see Faster onboarding: the value of a knowledge base and processes.
Access and attendance hardware can connect to the management back office, but devices do not solve countersign. How hardware and software meet: see Hardware-Software Integration. The usual order: clear roles first, run leave / expenses / seals, then let attendance rules come from the same leave ticket—not island first, bridge later.
Overtime and travel are the same bridge. A clock only knows who was there, not whether tonight counts as overtime. Without a ticket, HR at month-end accepts hallway talk or a group screenshot, and the dispute returns to “who decides.” Write overtime, makeup punches, and travel as chaseable tickets so punch data has an explanation.
If a growing company’s budget is tight, ship a minimum set of HR plus approvals: leave tickets write into attendance; expenses follow finance routing. Which flows first: see Growing companies: which approvals to ship first. To avoid the island, go to the Management systems service page and describe the current HR tools. Why management has to enter a system: see Why companies need a management system.